Echelon IP-852 Channel - Manual (Page 41)

IP-852 Channel User’s Guide 33
Figure 4.2 Setting up Multiple Firewalls with Multiple IP-852 Devices
6. Right-click the channel and click Update Members in the shortcut menu, or
right-click the device and select Update Device in the shortcut menu.
NAT Example: Simple Home Network
If you have a home network with DSL or cable Internet access, you can setup all of your
computers to communicate on the same IP address (assigned by your ISP) with the help
of a NAT gateway. Usually, addresses used in the private network (your home) are
taken from the range of addresses designated as “reserved” by the Internet Assigned
Numbers Authority (IANA). The subnets reserved for private use are as follows:
10.x.x.x or 10/8 (Class A)
172.16.x.x - 172.31.x.x or 172.16/12 (Class B)
192.168.x.x or 192.168/16 (Class C)
169.254.x.x or 169.254/16 – “Auto-configuration”
Note: Reserved addresses are reusable, but are not globally unique; therefore, they are
not routable on the Internet.
NAT translates the source addresses of outbound messages (sent by computers on your
home network) to a single address, making all of the computers on your home network
look like a single computer with a single IP address. When your home network receives
messages from an outside network, the NAT gateway “maps” the response to the proper
computer on your home network by changing the destination of the response to the
correct internal address, as in Figure 4.3.